CHARLESTON, W.Va. -- West Virginians should have been given clearer information that the 1-part-per-million screening level for the toxic chemical "Crude MCHM" was not a "bright line" between what exposures are safe and unsafe, a top U.S. Centers for Disease Control scientist said Wednesday.
Dr. Vikas Kapil, chief medical officer for the CDC's National Center for Environmental Health, also acknowledged that government officials could have moved more quickly in issuing an advisory that pregnant women drink only bottled water until chemical levels were zero in the West Virginia American Water system.
In an interview, Kapil said that the CDC was working with very limited data and in an emergency situation, but that agency officials could have communicated the uncertainties more carefully to the 300,000 residents whose water was contaminated.
"It would have been probably preferable to provide that kind of information up front," Kapil said.
"There are always things we can do to improve," he said. "It's a moving, dynamic situation where we really are doing the best we can."
West Virginia officials first mentioned the 1-part-per-million figure at a press conference on Friday, Jan. 10, the day after the Elk River spill. But both state officials and federal government representatives initially provided few details about how the number was derived.
Using the CDC's guidance, state officials and West Virginia American cleared residents to begin drinking the tap water starting on Monday evening, Jan. 13.
Then, on the night of Wednesday, Jan. 15, the state Department of Health and Human Resources announced that it was warning pregnant women to drink only bottled water -- at least for now.
Previously, officials have said that they added the advisory to pregnant women only out of "an abundance of caution" to protect developing fetuses. But a letter from the CDC to the DHHR suggested federal officials had obtained some additional studies that led to the advisory.
Kapil said he remains confident that the 1-part-per-million guidance is protective for most people, and that the region's water is safe, given that state sampling continues to show decreasing levels of Crude MCHM, with more and more samples listed with "non-detect" results.
In a statement issued Wednesday, West Virginia American Water President Jeff McIntyre said that "the majority of samples" are reading non-detectable.
"In the areas where sample results show levels above the non-detectable limit, they are still extremely low and only a fraction of the CDC-established 1 ppm health-protective limit," McIntyre said.
In a Wednesday letter to McIntyre, Sen. Jay Rockefeller, D-W.Va., asked West Virginia American for "maximum transparency," including Internet posting of results in "real time," including geographic coordinates of the samples, and the exact substances for which samples are being taken.